It's to Kylo's credit that he doesn't have anything to immediately say to that comment about Luke, though the thought of "Of course he did" is probably loud enough in the space between them for her to hear it regardless. His uncle had been scared of anything that so much as brushed the dark. He'd tried to hide it with regard to Kylo when he'd been younger, but he'd seen that quiet fear well before Luke had ever come after him with a lightsaber in his sleep.

The rest of that confession is more surprising. He had known from the first time they fought she had more connection to the dark than she would let herself acknowledge. And by now, he has a better idea of why, though he hasn't found the right moment to tell her what he had learned about her own grandfather, and he's not certain that the answer should be now, when she's already feeling such distress.

Not sure of any words at all, he goes a different route and lays his hand over one of hers where it grips the step between them, hoping that will provide some comfort, at least.